<!-- Licensed under a BSD license. See license.html for license -->
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=yes">
    <title>Three.js - Shadertoy Basic x40</title>
    <style>
    html, body {
        height: 100%;
        margin: 0;
    }
    #c {
        width: 100%;
        height: 100%;
        display: block;
    }
    </style>
  </head>
  <body>
    <canvas id="c"></canvas>
  </body>
<script type="importmap">
{
  "imports": {
    "three": "../../build/three.module.js"
  }
}
</script>

<script type="module">
import * as THREE from 'three';

function main() {

	const canvas = document.querySelector( '#c' );
	const renderer = new THREE.WebGLRenderer( { antialias: true, canvas } );
	renderer.autoClearColor = false;

	const camera = new THREE.OrthographicCamera(
		- 1, // left
		1, // right
		1, // top
		- 1, // bottom
		- 1, // near,
		1, // far
	);
	const scene = new THREE.Scene();
	const plane = new THREE.PlaneGeometry( 2, 2 );

	const fragmentShader = `
  #include <common>

  uniform vec3 iResolution;
  uniform float iTime;

  // By iq: https://www.shadertoy.com/user/iq
  // license: Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
  void mainImage( out vec4 fragColor, in vec2 fragCoord )
  {
      // Normalized pixel coordinates (from 0 to 1)
      vec2 uv = fragCoord/iResolution.xy;

      // Time varying pixel color
      vec3 col = 0.5 + 0.5*cos(iTime+uv.xyx*40.0+vec3(0,2,4));

      // Output to screen
      fragColor = vec4(col,1.0);
  }

  void main() {
    mainImage(gl_FragColor, gl_FragCoord.xy);
  }
  `;
	const uniforms = {
		iTime: { value: 0 },
		iResolution: { value: new THREE.Vector3() },
	};
	const material = new THREE.ShaderMaterial( {
		fragmentShader,
		uniforms,
	} );
	scene.add( new THREE.Mesh( plane, material ) );

	function resizeRendererToDisplaySize( renderer ) {

		const canvas = renderer.domElement;
		const width = canvas.clientWidth;
		const height = canvas.clientHeight;
		const needResize = canvas.width !== width || canvas.height !== height;
		if ( needResize ) {

			renderer.setSize( width, height, false );

		}

		return needResize;

	}

	function render( time ) {

		time *= 0.001; // convert to seconds

		resizeRendererToDisplaySize( renderer );

		const canvas = renderer.domElement;
		uniforms.iResolution.value.set( canvas.width, canvas.height, 1 );
		uniforms.iTime.value = time;

		renderer.render( scene, camera );

		requestAnimationFrame( render );

	}

	requestAnimationFrame( render );

}

main();
</script>
</html>
